EP1370601A1

EP1370601A1 - Method for the production of hydroxyalkyl polysiloxanes

Info

Publication number: EP1370601A1
Application number: EP02704693A
Authority: EP
Inventors: Oliver SCHÄFER; Thomas Kammel; Bernd Pachaly
Original assignee: Consortium fuer Elektrochemische Industrie GmbH
Current assignee: Consortium fuer Elektrochemische Industrie GmbH
Priority date: 2001-03-01
Filing date: 2002-02-07
Publication date: 2003-12-17
Anticipated expiration: 2022-02-07
Also published as: WO2002070586A1; DE50200870D1; CN1252141C; JP3848260B2; CN1494565A; US6943265B2; EP1370601B1; DE10109842A1; MY136760A; PL361656A1; JP2004527609A; US20040073031A1

Abstract

The invention relates to a method for the production of hydroxyalkyl polysiloxanes of general formula (V) (SiO4/2)k(R<1>SiO3/2)m(R<1>2SiO2/2)p(R<1>3SiO1/2)q [O1/2SiR<3>2-(CR<4>2)b-OH]s[O1/2H]t (V), wherein organosiloxanes of general formula (VI) (SiO4/2)k(R<1>SiO3/2)m(R<1>2Sio2/2)p(R<1>3SiO1/2)q[O1/2H]r (VI) containing silanol are made to react with compounds having at least one unit of general formula (IV) [O-(CR<4>2)b-SiR<3>2]n- (IV), wherein R<1>, R<3>, R<4>, b, s, r, n, t, k, m, p and q have the meaning cited in claim 1.

Description

Process for the preparation of hydroxyalkyl polysiloxanes

The invention relates to a process for the preparation of hydroxyalkylpolysiloxanes.

Hydroxyalkyl polysiloxanes and hydroxyalkyl silicone resins are used in many areas of application, e.g. in the cosmetics and textile industry. However, the commercial use of these compounds on an even larger scale is prevented by a relatively cumbersome manufacturing process. The direct hydrosilylation of protected or unprotected alkenols such as e.g. Allyl alcohol or hexenyl alcohol with alpha, omega-H-siloxanes. A disadvantage of this process is either the use of relatively expensive starting materials such as. B. platinum catalysts or hexenyl alcohol but also the side reaction occurring in the noble metal-catalyzed reaction of hydrogen elimination, which leads to hydrolytically unstable alkenyloxy end groups, which can be hydrolytically cleaved easily with elimination of alkenols. To avoid this side reaction, the used

Alcohols are protected, but the protective group has to be removed in a further process step. EP-A-629648 describes a further process which starts from special cyclic silanes of the general formula I which can react with HO-Si groups (silanol groups) at the end of a silicone chain without the use of catalysts.

O (CR ⁴ ₂ ) _b - SiR ³ ₂

(I)

R ^ is a carbon residue with up to 20 carbon atoms, R ^ is hydrogen or a hydrocarbon residue with up to 20 carbon atoms. These cycles can be reacted with silanol-terminated siloxanes of the general formula II HO (R ¹ ₂ SiO) _p H (II)

and give carbinol-terminated siloxanes of the general formula III.

HO- (CR ₂ ) b- ^siR3 2 ° ( ^Rl 2 ^si °) p ^siR3 2- ( ^CR4 2) b-OH (III)

It is emphasized that the reaction is carried out at temperatures between 25 ° C and 150 ° C without the use of catalysts.

In practice, however, there are some problems in performing this reaction. The β-membered ring with b = 4 can be obtained stably, but it requires an increased reaction temperature and significantly longer reaction times when reacting with silanol end groups. The 5-rings reactive in the sense of EP-A-629648 can be used in principle, but are unstable as a substance and tend to decompose. The method described in EP-A-629648 is therefore hardly suitable in terms of technical implementation.

The object of the present invention is therefore to develop an improved process for the preparation of hydroxyalkylpolysiloxanes.

The invention relates to a process for the preparation of hydroxyalkylpolysiloxanes of the general formula V.

(SiO ^4/2) k ^(Rl Siθ3 / ²⁾ m ^(Rl 2Si0 _^2/2) p ^(l 3SiOι / ²⁾ q

[0 _1/2 SiR ³ 2- (CR 2) b-OH] _s C0 ₁ / 2H] _t (V),

in the case of the silanol-containing organosiloxanes of the general formula VI

(Siθ4 2) ( ^Rl Siθ3 / 2 ⁾ m ^(l 2Si0 _2/2 ) p ( ^Rl 3 ^sio l / 2) q [Oi / 2H] _r (VI)

-V with compounds containing at least one unit of the general formula IV

- [0- ⁽ CR ⁴ ₂ ) b- ^siR3 2] n- ⁽ IV ⁾

have implemented, where

R, R3, R ^ is a hydrogen atom or a monovalent, optionally with -CN, -NCO, -NR ^X ₂ , -COOH, -COOR ^x , - halogen, -acrylic, -epoxy, -SH, -OH or -CONR ^x 2 substituted C] _- C2n hydrocarbon residue or C1-C15 hydrocarbonoxy residue, in each of which one or more methylene units which are not adjacent to one another are separated by groups -0-, -C0-, -C00-, -0C0-, or -OCOO-, - S-, or - NR ^X - can be replaced and in which one or more non-adjacent methine units can be replaced by groups, - N =, -N = N-, or -P =, R ^{x is} hydrogen or one optionally -CN or halogen substituted C_-Cιo ^{_Kohlen asserst} offrest, b values of at least 2, s values of at least 1, r values of at least 1, n values of at least 2 s + t the value of r and k + m + p + q Values of at least 2 mean.

The invention is based on the knowledge that linear siloxanes are also suitable for the functionalization of Si-OH groups. If compounds containing units of the general formula IV are used, they react easily and in a targeted manner with good yields with silanol end groups to give carbinols. Compounds which contain units of the general formula IV are stable and storable and are therefore particularly suitable for use on an industrial scale.

The _C] _-C20 ^-κ ° hlenwasserstoffreste and _C] _ ^-K-C20 ° hl ^enwass ER- be branched stoffoxyreste R ^1, R ^3, R ⁴ may be aliphatically saturated or unsaturated, aromatic, straight chain or. R ^, R ³ , R ⁴ preferably have 1 to 12 atoms, in particular 1 to 6 atoms, preferably only carbon atoms, or an alkoxy oxygen atom and otherwise only carbon atoms. R ¹ , R ³ , R ⁴ are preferably straight-chain or branched C _] _-Cg-alkyl radicals. The radicals methyl are particularly preferred,

Ethyl, phenyl, vinyl and trifluoropropyl.

The compounds of the general formula V are preferably prepared in which R ^{3 is} a methyl radical and R ^{4 is} hydrogen. B preferably has values of at most 50, in particular at most 10. In a particularly preferred embodiment, b is 3.

The hydroxy-functional organosiloxane of the general formula VI can be linear, cyclic or branched. The sum of k, m, p, q, s and t is preferably a number from 2 to 20,000, in particular 8 to 1,000. In order to enable a reaction between the organosiloxane which has units of the general formula IV and the linear siloxane, The organosiloxane of the general formula VI must contain hydroxyl groups.

A preferred variant for an organosiloxane of the general formula VI is a linear silicone polymer with k and m equal to 0, p greater than or equal to 1, q equal to 0 or 1 and r equal to 1 or 2, the condition q being equal to 2 minus r. Preferably r is s. The preferred organosiloxanes of the general formula VI can be either monomodal or multimodal, at the same time they can be in a narrow or very wide distribution.

Another preferred variant for a branched organosiloxane of the general formula VI used is an organosilicone resin. This can consist of several units, as indicated in the general formula VI, the mole percent of the units contained being designated by the indices k, m, p, q, r, s and t. A value of 0.1 to 20 mol% of units r is preferred, based on the sum before, k, m, p, q and r. At the same time, k + m> 0. When producing the organosiloxane resin of the general formula V, s> 0 and s + t must be r.

Resins are preferably produced in which 5% <k + m <90%, based on the sum of k, m, p, q, s and t, and preferably t is 0. In a particularly preferred case, the radical R ^{3 is} a methyl radical, R ¹ is a methyl radical and b is 3 and R ⁴ is hydrogen.

Preferably, as compounds that have at least one

Have unit of general formula IV, compounds of general formula VII

H- [0- (CR ⁴ ₂ ) b- ^siR3 2] n-0-X (VII),

used where

X is hydrogen or an optionally substituted with -CN or halogen C] _- -Cιo ^-Kon l ^enwasserst ° ffrest and

R ³ , R ⁴ , b and n have the meanings given above.

X is preferably hydrogen or a C1-C3 hydrocarbon radical, in particular methyl or ethyl radical.

Compounds of the general formula VII in which X is hydrogen can dimerize. However, the dimers react in the same way as the monomers with organosiloxanes of the general formula VI.

In the above formulas, fluorine, chlorine and bromine are preferred as halogen substituents.

The process can be carried out uncatalyzed, preferably at temperatures from 0 ° C. to 150 ° C. However, reaction temperatures of at least 100 ° C. are preferably used. However, the process can be improved by adding certain catalysts. These catalysts are acidic or basic compounds and cause both Response times and direction temperatures can be reduced.

The catalyst used is an inorganic or organic Lewis acid or Lewis base, such as organic Brönstedt acid or base, an organometallic compound or a halide salt.

As preferred acids, carboxylic acids, partly esterified carboxylic acids, particularly monocarboxylic acids, preferably formic acid or acetic acid or non-esterified or partially esterified mono- or oligo ^{'polyphosphoric} acids are used. Preferred bases are preferably

Alkylammonium hydroxides, ammonium alkoxides, alkylammonium fluorides or amine bases are used. Preferred organometallic reagents are organotin compounds, organotin compounds or organotitanium compounds. Preferred salts are tetraalkylammonium fluorides.

Phosphoric acids of the general formula VIII are preferred

0 = P (OR ² ) ₃ _ _v (OH) _v (VIII),

in the

R ^ is an optionally substituted linear or branched C] _- C30 alkyl, C2-C4Q alkenyl or alkoxyalkyl, C2-C 0 ~ ^R olyether, C5-Cχ4 cycloalkyl or -

Aryl radical and v represent the values 0, 1 or 2.

After the functionalization reaction of the silanol groups, the catalysts used are preferably deactivated by adding so-called anti-catalysts or catalyst poisons before they can lead to cleavage of the Si-O-Si groups. This side reaction depends on the catalyst used and does not necessarily have to occur, so that deactivation can also be dispensed with. Examples of catalyst poisons are when using bases such as acids and when using acids such as bases, which in the end results in a simple one Neutralization reaction leads. Depending on the use of the product, the corresponding reaction product between catalyst and catalyst poison can either be removed from the product or remain in the product. In the process for the preparation of hydroxyalkylpolysiloxanes of the general formula V, the amount of the compound used with units of the general formula IV depends on the amount r of the silanol groups to be functionalized in the organosiloxane of the general formula VI. If, however, complete functionalization of the OH groups is desired, the compound with units of the general formula IV must be added in at least equimolar amounts, based on n. If compound with units of the general formula IV is used in excess, the reacted compound can then either be cleaved thermolytically and then distilled off or hydrolyzed and then, if appropriate, likewise also distilled off.

If it is desired to prepare resins which have only a defined carbinol content s + t, the stoichiometric ratios between resin and compound with units of the general formula IV are selected so that the desired carbinol content is achieved. Remaining unreacted Si-OH groups can remain in the organofunctional siloxane of the general formula V - or, before or after the reaction with compound having units of the general formula IV, using, for example, silazanes of the general formula IX below

implemented in the

R> hydrogen or an optionally substituted with -CN or halogen C] _- C; L0 hydrocarbon residue ^{un <} ^ R ^{7 is} an optionally substituted with -CN or halogen C] _- Cιo ^{~ Kon} l ^enwasserst ° ffrest.

The hydrocarbon radicals R 1 and R ⁷ preferably have 1 to 5 carbon atoms. The radicals methyl, ethyl and vinyl are particularly preferred. Hydrogen is preferred as R ⁷ .

The process is preferably carried out at 0 ° C. to 160 ° C., particularly preferably at 40 ° C. to 100 ° C. The process can be carried out with the inclusion of solvents or without the use of solvents in suitable reactors. If necessary, work is carried out under vacuum or under positive pressure or at normal pressure (0.1 MPa).

When using solvents, inert, especially aprotic, solvents such as aliphatic hydrocarbons, e.g. Heptane or decane and aromatic hydrocarbons such as e.g. Toluene or xylene preferred. Ethers such as THF, diethyl ether or MTBE can also be used. The amount of solvent should be sufficient to ensure adequate homogenization of the reaction mixture. Solvents or solvent mixtures with a boiling point or boiling range of up to 120 ° C. at 0.1 MPa are preferred.

All of the above symbols of the above formulas have their meanings independently of one another.

In the following examples, unless stated otherwise, all quantities and percentages are based on weight, all pressures 0.10 MPa (abs.) And all temperatures 20 ° C. All viscosities were determined at 25 ° C.

Example 1 :

1000 g Me-siloxane (bishydroxy-terminated polydimethylsiloxane with a Mn of 3000 g / mol, determined by 1H-NMR

Spectroscopy) were reacted at 80 ° C. with 79.4 g of poly (1,1-dimethyl-1-sila-2-oxacyclopentane) with a viscosity of 40 mPas and 100 mg of formic acid. ^ H-NMR and 29si-NMR showed that after 4 hours all OH groups had been converted to hydroxypropyl units. To deactivate the catalyst, 500 mg of triethylamine were then added to the reaction solution and briefly distilled in vacuo (5 mbar) at 80 ° C. Pure bishydroxypropylpolydimethylsiloxane remained.

Example 2:

1000 g of Me-siloxane (bishydroxy-terminated polydimethylsiloxane with a Mn of 3000 g / mol, determined by 1H-NMR spectroscopy) were at 80 ° C with 77.6 g of poly (1, 1-dimethyl-l-sila-2 -oxacyclopentane) with a viscosity of 40 mPas and 100 mg formic acid. ^ H-NMR and 29si-NMR showed that after 4 hours no Si-OH groups and no poly (1, 1-dimethyl-l-sila-2-oxacyclopentane) were present. 97% of the desired product, bishydroxypropylpolydimethylsiloxane, and 3% of a partially esterified formic acid propyl hydroxypropylpolydimethylsiloxane were formed.

Example 3: 1000 g of siloxane (bishydroxy-terminated polydimethylsiloxane with a Mn of 28000 g / mol, determined by determining the OH number) were mixed with 8.4 g of poly (1, 1-dimethyl-l- sila-2-oxacyclopentane) with a viscosity of 40 mPas and 100 mg Arlypon® (partially esterified phosphoric acid from Grünau, Illertissen). 1 H-NMR and ²⁹ Si-NMR showed that after 3 hours all OH groups had been converted to hydroxypropyl units. To deactivate the catalyst, 500 mg of triethylamine were then added to the reaction solution and briefly distilled in vacuo (5 mbar) at 80 ° C. Pure bishydroxypropylpolydimethylsiloxane remained.

Example 4:

100 g of Me-siloxane (bishydroxy-terminated polydimethyl-siloxane with a Mn of 1000 g / mol, determined by 1H-NMR spectroscopy) were at 80 ° C with 23.4 g of poly (1, 1-dimethyl-l-sila -2-oxacyclopentane) with a viscosity of 40 mPas and 10 mg Arlypon®. ^ H-NMR and 29gi_NiiR showed that after 4 hours all OH groups had been converted to hydroxypropyl units were. To deactivate the catalyst, 500 mg of triethylamine were then added to the reaction solution and distilled briefly at 80 ° C. in vacuo (5 mbar). Pure bishydroxypropylpolydimethylsiloxane remained.

Example 5:

1000 g of silicone oil (bishydroxy-terminated polymethylvinylsiloxane with a vinyl: methyl ratio of 1: 4 and a Mn of 2800 g / mol, determined by IH NMR spectroscopy) were at 80 ° C. with 83.2 g of poly (1 , l-Dimet ^{'hyl-l-sila-2-oxacyclopentane)} having a viscosity of 60 mPas and 100 mg of formic acid. ¹ H-NMR and ²⁹ Si-NMR showed that after 3 hours all OH groups had been converted to hydroxypropyl units. To deactivate the catalyst, 500 mg of triethylamine were then added to the reaction solution and briefly distilled in vacuo (5 mbar) at 80 ° C. Pure bishydroxypropylpolydimethylsiloxane remained.

Example 6: 100 g of silicone oil (bishydroxy-terminated polymethyltrifluoropropylsiloxane with a trifluoropropyl: methyl ratio of 1: 1 and with a Mn of 900 g / mol, determined by IH-NMR spectroscopy) were measured at 80 ° C. with 26. 0 g of poly (1, l-dimethyl-l-sila-2-oxacyclopentane) with a viscosity of 60 mPas and 10 mg of formic acid. ^ H-NMR and ²⁹ Si-NMR showed that after 3 hours all OH groups had been converted to hydroxypropyl units. To deactivate the catalyst, 500 mg of triethylamine were then added to the reaction solution and distilled briefly at 80 ° C. in vacuo (5 mbar). What remained was pure

Bishydroxypropylpolydimethylsiloxane.

Example 7:

100 g of monohydroxy-terminated polydimethylsiloxane with a Mn of 3000 g / mol, determined by IH NMR spectroscopy) were at 80 ° C. with 3.9 g of poly (1, l-dimethyl-l-sila-2-oxacyclopentane ) with a viscosity of 110 mPas and 10 mg Arlypon® (partially esterified phosphoric acid from Grünau, Illertissen) implemented. ! H-NMR and ²⁹ Si-NMR showed that after 3 hours all OH groups had been converted to hydroxypropyl units and no broadening of the molecular weight was discernible. To deactivate the catalyst, 500 mg of triethylamine were then added to the reaction solution and distilled briefly at 80 ° C. in vacuo (5 mbar). Pure monohydroxypropylpolydimethylsiloxane remained.

Example 8: 100 g of monohydroxy-terminated polydimethylsiloxane with a Mn of 3000 g / mol, determined by IH NMR spectroscopy) were at 80 ° C. with 3.9 g of poly (1,1-dimethyl-l-sila- 2-oxacyclopentane) with a viscosity of 110 mPas and 50 mg of benzyltrimethylammonium hydroxide (40% solution in methanol). ^ H-NMR and ²⁹ Si-NMR showed that after 4 hours all OH groups had been converted to hydroxypropyl units and no broadening of the molecular weight was discernible. Then the catalyst was added 500 mg ^■ triethylamine to the reaction solution to deactivate and (mbar 5) briefly distilled under vacuum at 80 ° C. Pure monohydroxypropylpolydimethylsiloxane remained.

Claims

claims

1. Process for the preparation of hydroxyalkylpolysiloxanes of the general formula V

(SiO ^4/2) k ^(Rl Si0 _3/2) m ^(Rl 2Siθ2 / ²⁾ p ^(R 3 ^SiO l / ²⁾ q

[0 _1/2 SiR3 ₂ - (CR ⁴ ₂ ) _b -OH] _s [0 _{1 2} H] _t (V),

in the case of the silanol-containing organosiloxanes of the general formula VI

(SiO 4 2) k ^(Rl Siθ3 / 2) m ^(Rl 2Siθ2 / 2) p ^(R 3Si0 _1/2) q [0 _{_1/2} H] _r (VI)

with compounds containing at least one unit of the general formula IV

- [0- ⁽ CR ⁴ ₂ ⁾ b- ^siR3 2] n- ⁽ IV ⁾

have, are implemented, where R ¹ , R ³ , R ^{4 is} a hydrogen atom or a monovalent, optionally with -CN, -NCO, -NR ^X , -COOH, -C00R ^X , - halogen, -acrylic, -epoxy, -SH, -OH or -C0NR ^X substituted Cχ-C20 ~ hydrocarbon residue or Cχ-Cχ5 ~

Hydrocarbonoxy radical, in each of which one or more methylene units which are not adjacent to one another can be replaced by groups -0-, -CO-, -COO-, -OCO-, or -0C00-, -S-, or - NR ^X - and in which one or more methine units, which are not adjacent to one another, can be replaced by groups, - N =, -N = N-, or -P =, R ^{x is} hydrogen or a Cχ-Cχg hydrocarbon radical which is optionally substituted by -CN or halogen, b values of at least 2, s values of at least 1, r values of at least 1, n values of at least 2 s + t the value of r and k + m + jfr + q values of at least 2.

2. The method according to claim 1, wherein R ^{1 is} methyl, ethyl, phenyl, vinyl or trifluoropropyl.

3. The method of claim 1 or 2, wherein R ^{4 is} hydrogen.

4. The method according to claim 1 to 3, wherein R ^{3 is} a methyl radical.

5. The method according to claim 1 to 4, in which a linear organosiloxane of the general formula VI is used, in which k and m equal to 0, p greater than or equal to 1, q equal to 0 or 1 and r equal to 1 or 2.

6. The method according to claim 1 to 4, in which resins are produced in which 5% <k + m <90%, based on the sum of k, m, p, q, s and t.

7. The method according to claim 1 to 6, wherein the reaction temperature is 0 ° C to 160 ° C.

8. The method according to claim 1 to 7, in which a catalyst is used which is an inorganic or organic Lewis acid or Lewis base.

9. The method according to claim 8, wherein the catalyst is selected from carboxylic acids, partially esterified carboxylic acids, unesterified or partially esterified mono-oligo or polyphosphoric acids, alkylammonium hydroxides, ammonium alkoxides, al ylammonium fluorides and amine bases.